Method for producing SiC substrate

Abstract

A method for producing a SiC substrate with an epitaxial layer, which can prevent inventory of wafers from unduly increasing and wasteful production, is provided. This is achieved by a method for producing a SiC substrate with an epitaxial layer one at a time, the method comprising growing an epitaxial layer and growing a SiC substrate on a seed crystal substrate, and the method further comprising removing the obtained SiC substrate with the epitaxial layer from the seed crystal substrate.

What is claimed is: 
     
       1. A method for producing an SiC substrate with an epitaxial layer one at a time,
 the method comprising growing a SiC epitaxial layer on a seed crystal substrate by a solution process using a Si molten liquid and growing a SiC substrate on the grown SiC epitaxial layer by a solution process, and 
 the method further comprising removing the obtained SiC substrate with the SiC epitaxial layer from the seed crystal substrate, 
 wherein the nitrogen density of the SiC epitaxial layer is 10 17 /cm 3  or less, and 
 the nitrogen density of the SiC substrate is 10 18 /cm 3  or greater. 
 
     
     
       2. The method according to  claim 1 , wherein the growing the SiC substrate by the solution process comprises using a Si/X molten liquid, wherein X is selected from Ti, Mn, Cr, Ni, Ce, Co, V and Fe. 
     
     
       3. The method according to  claim 1 , wherein the seed crystal substrate has been CMP-polished. 
     
     
       4. The method according to  claim 1 , wherein the growing the SiC epitaxial layer comprises conducting onset-growth. 
     
     
       5. The method according to  claim 1 , wherein the growing the SiC epitaxial layer comprises conducting (000-1) C-surface growth or (0001) Si-surface growth. 
     
     
       6. The method according to  claim 1 , wherein the growing the SiC substrate comprises conducting (000-1) C-surface growth or (0001) Si-surface growth. 
     
     
       7. The method according to  claim 1 , wherein the growing the SiC epitaxial layer comprises growing the SiC epitaxial layer to a thickness of 5 to 200 μm, and the growing the SiC substrate comprises growing the SiC substrate to a thickness of 150 to 500 μm.